Complete Certain Challenges To Unlock Following Riders.

Rider	How to unlock
Alex Barros	Complete Challenge 17.
Alex Criville	Complete Challenge 8.
Carlos Checa	Complete Challenge 15.
Gun Koma	Complete Challenge 24.
Haruchika Aoki	Complete Challenge 2.
Jean Michel Bayle	Complete Challenge 4.
John Kocinski	Complete Challenge 9.
Jose Luis Cardoso	Complete Challenge 11.
Juan Borja	Complete Challenge 3.
Jurgen Vd Goorbergh	Complete Challenge 1.
K1	Complete Challenge 23.
Kenny Roberts	Complete Challenge 10.
Klonoa	Complete Challenge 22.
Max Biaggi	Complete Challenge 16.
Mick Doohan	Complete Challenge 21.
Mike Hale	Complete Challenge 12.
Nobuatsu Aoki	Complete Challenge 5.
Norick Abe	Complete Challenge 6.
Regis Laconi	Complete Challenge 13.
Sete Gibernau	Complete Challenge 18.
Simon Crafar	Complete Challenge 7.
Tadayuki Okada	Complete Challenge 19.
Takuma Aoki	Complete Challenge 14.
Tetsuya Harada	Complete Challenge 20.